/*
 * Copyright (C) 2010 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*namespace com.google.zxing.common {*/

/*import java.nio.charset.Charset;*/
/*import java.util.Map;*/

import DecodeHintType from '../DecodeHintType';
import CharacterSetECI from './CharacterSetECI';
import StringEncoding from '../util/StringEncoding';
import {int, char} from '../../customTypings';
import Charset from '../util/Charset';
import StringBuilder from '../util/StringBuilder';

/**
 * Common string-related functions.
 *
 * @author Sean Owen
 * @author Alex Dupre
 */
export default class StringUtils {

  public static SHIFT_JIS = CharacterSetECI.SJIS.getName(); // "SJIS"
  public static GB2312 = 'GB2312';
  public static ISO88591 = CharacterSetECI.ISO8859_1.getName(); // "ISO8859_1"
  private static EUC_JP = 'EUC_JP';
  private static UTF8 = CharacterSetECI.UTF8.getName(); // "UTF8"
  private static PLATFORM_DEFAULT_ENCODING = StringUtils.UTF8; // "UTF8"//Charset.defaultCharset().name()
  private static ASSUME_SHIFT_JIS = false;
  // SHIFT_JIS.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING) ||
  // EUC_JP.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING);

  static castAsNonUtf8Char(code: number, encoding: Charset = null) {
    // ISO 8859-1 is the Java default as UTF-8 is JavaScripts
    // you can see this method as a Java version of String.fromCharCode
    const e = encoding ? encoding.getName() : this.ISO88591;
    // use passed format (fromCharCode will return UTF8 encoding)
    return StringEncoding.decode(new Uint8Array([code]), e);
  }

  /**
   * @param bytes bytes encoding a string, whose encoding should be guessed
   * @param hints decode hints if applicable
   * @return name of guessed encoding; at the moment will only guess one of:
   *  {@link #SHIFT_JIS}, {@link #UTF8}, {@link #ISO88591}, or the platform
   *  default encoding if none of these can possibly be correct
   */
  public static guessEncoding(bytes: Uint8Array, hints: Map<DecodeHintType, any>): string {
    if (hints !== null && hints !== undefined && undefined !== hints.get(DecodeHintType.CHARACTER_SET)) {
      return hints.get(DecodeHintType.CHARACTER_SET).toString();
    }
    // For now, merely tries to distinguish ISO-8859-1, UTF-8 and Shift_JIS,
    // which should be by far the most common encodings.
    const length = bytes.length;
    let canBeISO88591 = true;
    let canBeShiftJIS = true;
    let canBeUTF8 = true;
    let utf8BytesLeft = 0;
    // int utf8LowChars = 0
    let utf2BytesChars = 0;
    let utf3BytesChars = 0;
    let utf4BytesChars = 0;
    let sjisBytesLeft = 0;
    // int sjisLowChars = 0
    let sjisKatakanaChars = 0;
    // int sjisDoubleBytesChars = 0
    let sjisCurKatakanaWordLength = 0;
    let sjisCurDoubleBytesWordLength = 0;
    let sjisMaxKatakanaWordLength = 0;
    let sjisMaxDoubleBytesWordLength = 0;
    // int isoLowChars = 0
    // int isoHighChars = 0
    let isoHighOther = 0;

    const utf8bom = bytes.length > 3 &&
      bytes[0] === /*(byte) */0xEF &&
      bytes[1] === /*(byte) */0xBB &&
      bytes[2] === /*(byte) */0xBF;

    for (let i = 0;
      i < length && (canBeISO88591 || canBeShiftJIS || canBeUTF8);
      i++) {

      const value = bytes[i] & 0xFF;

      // UTF-8 stuff
      if (canBeUTF8) {
        if (utf8BytesLeft > 0) {
          if ((value & 0x80) === 0) {
            canBeUTF8 = false;
          } else {
            utf8BytesLeft--;
          }
        } else if ((value & 0x80) !== 0) {
          if ((value & 0x40) === 0) {
            canBeUTF8 = false;
          } else {
            utf8BytesLeft++;
            if ((value & 0x20) === 0) {
              utf2BytesChars++;
            } else {
              utf8BytesLeft++;
              if ((value & 0x10) === 0) {
                utf3BytesChars++;
              } else {
                utf8BytesLeft++;
                if ((value & 0x08) === 0) {
                  utf4BytesChars++;
                } else {
                  canBeUTF8 = false;
                }
              }
            }
          }
        } // else {
        // utf8LowChars++
        // }
      }

      // ISO-8859-1 stuff
      if (canBeISO88591) {
        if (value > 0x7F && value < 0xA0) {
          canBeISO88591 = false;
        } else if (value > 0x9F) {
          if (value < 0xC0 || value === 0xD7 || value === 0xF7) {
            isoHighOther++;
          } // else {
          // isoHighChars++
          // }
        } // else {
        // isoLowChars++
        // }
      }

      // Shift_JIS stuff
      if (canBeShiftJIS) {
        if (sjisBytesLeft > 0) {
          if (value < 0x40 || value === 0x7F || value > 0xFC) {
            canBeShiftJIS = false;
          } else {
            sjisBytesLeft--;
          }
        } else if (value === 0x80 || value === 0xA0 || value > 0xEF) {
          canBeShiftJIS = false;
        } else if (value > 0xA0 && value < 0xE0) {
          sjisKatakanaChars++;
          sjisCurDoubleBytesWordLength = 0;
          sjisCurKatakanaWordLength++;
          if (sjisCurKatakanaWordLength > sjisMaxKatakanaWordLength) {
            sjisMaxKatakanaWordLength = sjisCurKatakanaWordLength;
          }
        } else if (value > 0x7F) {
          sjisBytesLeft++;
          // sjisDoubleBytesChars++
          sjisCurKatakanaWordLength = 0;
          sjisCurDoubleBytesWordLength++;
          if (sjisCurDoubleBytesWordLength > sjisMaxDoubleBytesWordLength) {
            sjisMaxDoubleBytesWordLength = sjisCurDoubleBytesWordLength;
          }
        } else {
          // sjisLowChars++
          sjisCurKatakanaWordLength = 0;
          sjisCurDoubleBytesWordLength = 0;
        }
      }
    }

    if (canBeUTF8 && utf8BytesLeft > 0) {
      canBeUTF8 = false;
    }
    if (canBeShiftJIS && sjisBytesLeft > 0) {
      canBeShiftJIS = false;
    }

    // Easy -- if there is BOM or at least 1 valid not-single byte character (and no evidence it can't be UTF-8), done
    if (canBeUTF8 && (utf8bom || utf2BytesChars + utf3BytesChars + utf4BytesChars > 0)) {
      return StringUtils.UTF8;
    }
    // Easy -- if assuming Shift_JIS or at least 3 valid consecutive not-ascii characters (and no evidence it can't be), done
    if (canBeShiftJIS && (StringUtils.ASSUME_SHIFT_JIS || sjisMaxKatakanaWordLength >= 3 || sjisMaxDoubleBytesWordLength >= 3)) {
      return StringUtils.SHIFT_JIS;
    }
    // Distinguishing Shift_JIS and ISO-8859-1 can be a little tough for short words. The crude heuristic is:
    // - If we saw
    //   - only two consecutive katakana chars in the whole text, or
    //   - at least 10% of bytes that could be "upper" not-alphanumeric Latin1,
    // - then we conclude Shift_JIS, else ISO-8859-1
    if (canBeISO88591 && canBeShiftJIS) {
      return (sjisMaxKatakanaWordLength === 2 && sjisKatakanaChars === 2) || isoHighOther * 10 >= length
        ? StringUtils.SHIFT_JIS : StringUtils.ISO88591;
    }

    // Otherwise, try in order ISO-8859-1, Shift JIS, UTF-8 and fall back to default platform encoding
    if (canBeISO88591) {
      return StringUtils.ISO88591;
    }
    if (canBeShiftJIS) {
      return StringUtils.SHIFT_JIS;
    }
    if (canBeUTF8) {
      return StringUtils.UTF8;
    }

    // Otherwise, we take a wild guess with platform encoding
    return StringUtils.PLATFORM_DEFAULT_ENCODING;
  }

  /**
   *
   * @see https://stackoverflow.com/a/13439711/4367683
   *
   * @param append The new string to append.
   * @param args Argumets values to be formated.
   */
  public static format(append: string, ...args: any[]) {

    let i = -1;

    function callback(exp: string | number, p0: any, p1: any, p2: any, p3: any, p4: any) {

      if (exp === '%%') return '%';
      if (args[++i] === undefined) return undefined;

      exp = p2 ? parseInt(p2.substr(1)) : undefined;

      let base = p3 ? parseInt(p3.substr(1)) : undefined;
      let val: string;

      switch (p4) {
        case 's': val = args[i]; break;
        case 'c': val = args[i][0]; break;
        case 'f': val = parseFloat(args[i]).toFixed(exp); break;
        case 'p': val = parseFloat(args[i]).toPrecision(exp); break;
        case 'e': val = parseFloat(args[i]).toExponential(exp); break;
        case 'x': val = parseInt(args[i]).toString(base ? base : 16); break;
        case 'd': val = parseFloat(parseInt(args[i], base ? base : 10).toPrecision(exp)).toFixed(0); break;
      }

      val = typeof val === 'object' ? JSON.stringify(val) : (+val).toString(base);
      let size = parseInt(p1); /* padding size */
      let ch = p1 && (p1[0] + '') === '0' ? '0' : ' '; /* isnull? */

      while (val.length < size) val = p0 !== undefined ? val + ch : ch + val; /* isminus? */

      return val;
    }

    let regex = /%(-)?(0?[0-9]+)?([.][0-9]+)?([#][0-9]+)?([scfpexd%])/g;

    return append.replace(regex, callback);
  }

  /**
   *
   */
  public static getBytes(str: string, encoding: CharacterSetECI): Uint8Array {
    return StringEncoding.encode(str, encoding);
  }

  /**
   * Returns the charcode at the specified index or at index zero.
   */
  public static getCharCode(str: string, index = 0): int {
    return str.charCodeAt(index);
  }

  /**
   * Returns char for given charcode
   */
  public static getCharAt(charCode: number): string {
    return String.fromCharCode(charCode);
  }

  /**
   * Tells whether or not this encoder can encode the given character.
   * @param ch  The given character
   * @param encoding true if, and only if, this encoder can encode the given character
   */
  public static canEncode(ch: char, encoding: CharacterSetECI): boolean {
    let charAt = StringUtils.getCharAt(ch);
    let bytes = StringUtils.getBytes(charAt, encoding);
    return bytes !== undefined && bytes.length !== 0;
  }

  /**
   * Returns true if, and only if, length() is 0.
   * @param text text
   * Returns:true if length() is 0, otherwise false
   */
  public static isEmpty(text: string): boolean {
    if (text === undefined) {
      return true;
    }
    if (text.length === 0) {
      return true;
    }
  }

  /**
   * Returns the string representation of the char array argument. The contents of the character array are copied; subsequent modification of the character array does not affect the returned string.
   * Params:data – the character array.
   * @param array the character array.
   * Returns:a String that contains the characters of the character array.
   */
  public static valueOf(array: Int32Array): string {
    let sb: StringBuilder = new StringBuilder();
    for (let element of array) {
      sb.append(StringUtils.getCharAt(element));
    }
    return sb.toString();
  }
}
